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Diffstat (limited to 'include/led.h')
-rw-r--r-- | include/led.h | 295 |
1 files changed, 295 insertions, 0 deletions
diff --git a/include/led.h b/include/led.h new file mode 100644 index 00000000000..2a7f38bf84b --- /dev/null +++ b/include/led.h @@ -0,0 +1,295 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Copyright (c) 2015 Google, Inc + * Written by Simon Glass <sjg@chromium.org> + */ + +#ifndef __LED_H +#define __LED_H + +#include <stdbool.h> +#include <cyclic.h> +#include <dm/ofnode.h> + +/** + * DOC: Overview + * + * Generic LED API provided when a supported compatible is defined in DeviceTree. + * + * To enable support for LEDs, enable the `CONFIG_LED` Kconfig option. + * + * The most common implementation is for GPIO-connected LEDs. If using GPIO-connected LEDs, + * enable the `LED_GPIO` Kconfig option. + * + * `LED_BLINK` support requires LED driver support and is therefore optional. If LED blink + * functionality is needed, enable the `LED_BLINK` Kconfig option. If LED driver doesn't + * support HW Blink, SW Blink can be used with the Cyclic framework by enabling the + * CONFIG_LED_SW_BLINK. + * + * Boot and Activity LEDs are also supported. These LEDs can signal various system operations + * during runtime, such as boot initialization, file transfers, and flash write/erase operations. + * + * To enable a Boot LED, enable `CONFIG_LED_BOOT` and define in `/options/u-boot` root node the + * property `boot-led`. This will enable the specified LED to blink and turn ON when + * the bootloader initializes correctly. + * + * To enable an Activity LED, enable `CONFIG_LED_ACTIVITY` and define in `/options/u-boot` root + * node the property `activity-led`. + * This will enable the specified LED to blink and turn ON during file transfers or flash + * write/erase operations. + * + * Both Boot and Activity LEDs provide a simple API to turn the LED ON or OFF: + * `led_boot_on()`, `led_boot_off()`, `led_activity_on()`, and `led_activity_off()`. + * + * Both configurations can optionally define a `boot/activity-led-period` property + * if `CONFIG_LED_BLINK` or `CONFIG_LED_SW_BLINK` is enabled for LED blink operations, which + * is usually used by the Activity LED. If not defined the default value of 250 (ms) is used. + * + * When `CONFIG_LED_BLINK` or `CONFIG_LED_SW_BLINK` is enabled, additional APIs are exposed: + * `led_boot_blink()` and `led_activity_blink()`. Note that if `CONFIG_LED_BLINK` or + * `CONFIG_LED_SW_BLINK` is disabled, these APIs will behave like the `led_boot_on()` and + * `led_activity_on()` APIs, respectively. + */ + +struct udevice; + +/* + * value imported from linux:include/linux/uapi/linux/uleds.h + */ +#define LED_MAX_NAME_SIZE 64 + +enum led_state_t { + LEDST_OFF = 0, + LEDST_ON = 1, + LEDST_TOGGLE, + LEDST_BLINK, + + LEDST_COUNT, +}; + +enum led_sw_blink_state_t { + LED_SW_BLINK_ST_DISABLED, + LED_SW_BLINK_ST_NOT_READY, + LED_SW_BLINK_ST_OFF, + LED_SW_BLINK_ST_ON, +}; + +struct led_sw_blink { + enum led_sw_blink_state_t state; + struct udevice *dev; + struct cyclic_info cyclic; + const char cyclic_name[0]; +}; + +/** + * struct led_uc_plat - Platform data the uclass stores about each device + * + * @label: LED label + * @default_state: LED default state + * @name: LED name, derived from function, color or function-enumerator + * property. + * @sw_blink: LED software blink struct + */ +struct led_uc_plat { + const char *label; + enum led_state_t default_state; + char name[LED_MAX_NAME_SIZE]; +#ifdef CONFIG_LED_SW_BLINK + struct led_sw_blink *sw_blink; +#endif +}; + +/** + * struct led_uc_priv - Private data the uclass stores about each device + * + * @boot_led_label: Boot LED label + * @activity_led_label: Activity LED label + * @boot_led_dev: Boot LED dev + * @activity_led_dev: Activity LED dev + * @boot_led_period: Boot LED blink period + * @activity_led_period: Activity LED blink period + */ +struct led_uc_priv { +#ifdef CONFIG_LED_BOOT + const char *boot_led_label; + int boot_led_period; +#endif +#ifdef CONFIG_LED_ACTIVITY + const char *activity_led_label; + int activity_led_period; +#endif +}; + +struct led_ops { + /** + * set_state() - set the state of an LED + * + * @dev: LED device to change + * @state: LED state to set + * @return 0 if OK, -ve on error + */ + int (*set_state)(struct udevice *dev, enum led_state_t state); + + /** + * led_get_state() - get the state of an LED + * + * @dev: LED device to change + * @return LED state led_state_t, or -ve on error + */ + enum led_state_t (*get_state)(struct udevice *dev); + +#ifdef CONFIG_LED_BLINK + /** + * led_set_period() - set the blink period of an LED + * + * Thie records the period if supported, or returns -ENOSYS if not. + * To start the LED blinking, use set_state(). + * + * @dev: LED device to change + * @period_ms: LED blink period in milliseconds + * @return 0 if OK, -ve on error + */ + int (*set_period)(struct udevice *dev, int period_ms); +#endif +}; + +#define led_get_ops(dev) ((struct led_ops *)(dev)->driver->ops) + +/** + * led_get_by_label() - Find an LED device by label + * + * @label: LED label to look up + * @devp: Returns the associated device, if found + * Return: 0 if found, -ENODEV if not found, other -ve on error + */ +int led_get_by_label(const char *label, struct udevice **devp); + +/** + * led_set_state() - set the state of an LED + * + * @dev: LED device to change + * @state: LED state to set + * Return: 0 if OK, -ve on error + */ +int led_set_state(struct udevice *dev, enum led_state_t state); + +/** + * led_get_state() - get the state of an LED + * + * @dev: LED device to change + * Return: LED state led_state_t, or -ve on error + */ +enum led_state_t led_get_state(struct udevice *dev); + +/** + * led_set_period() - set the blink period of an LED + * + * @dev: LED device to change + * @period_ms: LED blink period in milliseconds + * Return: 0 if OK, -ve on error + */ +int led_set_period(struct udevice *dev, int period_ms); + +/** + * led_bind_generic() - bind children of parent to given driver + * + * @parent: Top-level LED device + * @driver_name: Driver for handling individual child nodes + */ +int led_bind_generic(struct udevice *parent, const char *driver_name); + +/* Internal functions for software blinking. Do not use them in your code */ +int led_sw_set_period(struct udevice *dev, int period_ms); +bool led_sw_is_blinking(struct udevice *dev); +bool led_sw_on_state_change(struct udevice *dev, enum led_state_t state); + +#ifdef CONFIG_LED_BOOT + +/** + * led_boot_on() - turn ON the designated LED for booting + * + * Return: 0 if OK, -ve on error + */ +int led_boot_on(void); + +/** + * led_boot_off() - turn OFF the designated LED for booting + * + * Return: 0 if OK, -ve on error + */ +int led_boot_off(void); + +#if defined(CONFIG_LED_BLINK) || defined(CONFIG_LED_SW_BLINK) +/** + * led_boot_blink() - turn ON the designated LED for booting + * + * Return: 0 if OK, -ve on error + */ +int led_boot_blink(void); + +#else +/* If LED BLINK is not supported/enabled, fallback to LED ON */ +#define led_boot_blink led_boot_on +#endif +#else +static inline int led_boot_on(void) +{ + return -ENOSYS; +} + +static inline int led_boot_off(void) +{ + return -ENOSYS; +} + +static inline int led_boot_blink(void) +{ + return -ENOSYS; +} +#endif + +#ifdef CONFIG_LED_ACTIVITY + +/** + * led_activity_on() - turn ON the designated LED for activity + * + * Return: 0 if OK, -ve on error + */ +int led_activity_on(void); + +/** + * led_activity_off() - turn OFF the designated LED for activity + * + * Return: 0 if OK, -ve on error + */ +int led_activity_off(void); + +#if defined(CONFIG_LED_BLINK) || defined(CONFIG_LED_SW_BLINK) +/** + * led_activity_blink() - turn ON the designated LED for activity + * + * Return: 0 if OK, -ve on error + */ +int led_activity_blink(void); +#else +/* If LED BLINK is not supported/enabled, fallback to LED ON */ +#define led_activity_blink led_activity_on +#endif +#else +static inline int led_activity_on(void) +{ + return -ENOSYS; +} + +static inline int led_activity_off(void) +{ + return -ENOSYS; +} + +static inline int led_activity_blink(void) +{ + return -ENOSYS; +} +#endif + +#endif |